Why, oh why does a new setup added to the game not show up. You're on a track you haven't raced and you add a setup they refuses to appear...

if its being downloaded, you have to 'refresh' the list, you can easily do so by changing cars, and/or exit pits, enter pits, and that should work too

That's what I normally do, but of late it doesn't help at all...

restart the game

Some download methods might change any spaces in the setup filename to _ which doesn't work. Filename prefixes need to be written with spaces, ie. "FORMULA V8_aston" shows up properly in LFS, "FORMULA_V8_aston" doesn't.

Check your data\settings folder for such errors.